Too much light?

[TAXMAN]

Thanks Brett.

The coral problem was most of my softies shriveled up and lost color and the SPS would bleach and start to loose tissue. I tought it was the chemical battle of the different types of corals, but I found my temp probe to be bad and the tank was running from 84-89 for about 3 weeks. Thats when I put the carbon in and then found the temp problem a few days later. I only left the carbon in due to most of the people that replied here and on RC run it all the time. Just to keep the water clean and not take chances I guess.

[Brett Wilson]

yeah, I prefer clean water myself, just like where the corals live in nature - nutrient depleted water.

[SueT]

Taxman, I ran 400w 65k iwasaki's over a year, several years back. Basically the only reason I got rid of them was the heat they put off and my chiller couldn't keep up. During that time I had some of the best growth and coloration I've ever had in my acropora collection. I opted to go back to the 250w iwasaki's. I was able to raise my canopy and lower it to acclimate my corals. This was on a 120g with 2 lights. I know that several of my sps friends have had 400w iwasaki's but most have also switched to some sort of 10k now. Myself included.{Thanks to Jim Norris}. I also run carbon 24/7 and just started using ROWAphos too.

I don't think your temp is bad but I wouldn't let it get any higher. I keep mine at 77-78. I think I have to agree with the ideas your lights may be too low. I literally burned my arm working in that tank when I had the 400w iwasaki's on it. If it could burn my arm I'd hate to think what they can do to corals.

[Tim Marvin]

I run my halides 5 inches from the water. The lower the better in my opinion. One thing that everyone is overlooking here is water changes. Your doing 18 gallons per week? That is 10% if you had nothing else in the tank. If your tank is loaded with rock then you are doing more like a 20% or more since the rock is displacing a lot of water. If it is 180 gallon tank full of rock you probably only have 80-90 gallons of water. Times that by 4 weeks and your doing 80% per month! I used to beleive it was helping my tank by having such perfectly clean water, but I couldn't have been more wrong. I lost a lot of the mushrooms I had, most corals shiveled up to near nothing and sps turned brown. Even the anemones didn't like it. At the same time I had a tank, that I neglected, (IMO), and after scaping the green off the glass I realized it was exploding in life and growth! I learned that too much water changing can also be a very bad thing. I quit changing so much water and everything came back. I don't even do water changes on the prop tank any more other than making up water as I sell frags so it realistically gets about a 20% change just from selling frags. I did up grade the tank system recently to the Norris prop tank so it got a small water change. What I am trying to state here is: too much water changing can also kill your livestock. Stick to about 3-5 gallons per week and see if that helps. Maybe not even do a water change for several weeks before you start the new schedule.

[Brett Wilson]

Good points Tim; I totally ignored that fact.

[prof]

How is your water flow? Too much or too little can cause what you are describing.

[Tim Marvin]

Birdsnest need intense light and high flow. They would die on the sandbed anyway.